The bad news beetles

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Twenty years ago, you never heard of anyone having problems with European Chafer Beetle larvae (grubs). It was always Japanese Beetle grubs that were (and still are) the big problem. I was aware that folks to our west in Rochester and Buffalo had “another” beetle, but it was rare to hear of them in the Capital District. Not any more. During the last few years there seems to have been an uptick in the number of Chafer sightings in the area. Someone just mentioned to me today that they are finding fewer Japanese Beetles in their swimming pool’s skimmer this year but more of the dun-colored European Chafer Beetles. Pool skimmer data is probably as accurate as any.

European Chafer Beetle

Japanese Beetles

Good news…lots of grubs drowned in hurricane rains last year
I had suspected that there might be fewer Japanese Beetles this year since many of them would have drown in the super-saturated soil that arrived with hurricane Irene on August 28th last year. This would have been when the grubs were tiny since they’d just hatched. If soil stays saturated long enough, the tiny grubs will drown. It would seem that did actually happen to some degree since, from what I’m hearing, there are fewer Japanese Beetles than normal. At least there is something good that came out of last year’s hurricanes.

Bad news…plenty survived in sandy areas
Areas with sandy soil (which includes much of the Albany Basin) still seem to have plenty of Japanese Beetles. Since sandy soil drains so quickly, the grubs don’t drown as easily.

The good news about European Chafers
We all know of the devastation that Japanese Beetles can cause in our gardens. They eat the leaves off our beans and roses and a host of other plants. We see them and we know them.

Chafer Beetles, on the other hand, don’t eat at all. They just hatch, mate and the females lay eggs during their short life. This is why they go almost unnoticed since you’ll never encounter them eatiing your plants. That’s the good news.

The bad news about European Chafers
The bad news is that European Chafer Beetles lay their eggs into the soil of our lawns, and they cause the same damage to the roots of sunny lawns that Japanese Beetle grubs do. In fact, you’d need a microscope to tell one from the other.

Meet the rest of the bad news beetles
There are also lesser known beetles that lay their eggs in your lawn that hatch into grubs that eat the roots. They are the June Bugs, Oriental Beetles, Asiatic Beetles and Rose Chafer Beetles. All these beetles produce grubs that eat grass roots during August and September. Collectively they are called “white grubs” or “white lawn grubs”.

The bad news about lawn grubs
The bad news is that our lovely spring lawns are struggling to survive the current dry spell, and it looks as though there is no real relief in sight. This will weaken our lawns and make the damage from all the grubs that will be hatching during August and September more damaging than normal.

Controlling lawn grubs with a pre-emptive strike
In the past, we’d let the grubs hatch and then use a strong contact killer (like diazinon) to kill them in late September. Of course these contact killers weren’t the friendliest chemicals around, and they’ve been removed from the marketplace in favor of safer methods. Since we’ve abandoned these abusive “shotgun” chemicals, timing becomes more critical.

If you treated this spring, you killed LAST YEAR’S GRUBS
There’s so much confusion about grub control that garden centers will sell a lot more grub control in the spring than in summer when, logically, it should be the other way around. I’m sure much of this has to do with the fact that the damage grubs do in late summer and fall isn’t visible until the following spring.

Know the enemy
The first step is to understand the life cycle of the Japanese Beetle. Let’s start at the beginning. After feasting on your beans and rose bushes, the female Japanese Beetle lays her eggs in the warm sunny areas of your lawn starting in mid-August. The healthiest grass is growing in the sunny areas of your beautiful lawn that you’ve worked on all spring. She won’t lay her eggs in the shade since soil temperatures are too low to keep the eggs alive. Each female is capable of laying a couple of hundred eggs. These eggs will all hatch within four days after they’re laid. Are you listening? There are no grubs hatching in the spring. None. They ALL hatch from mid-August through September.

After the tiny grubs hatch in mid-August and September, they start eating. What they eat are the roots of your lawn. They eat and eat and eat and eat so that, just like a bear, they have enough fat stored to hibernate for the winter.

As the soil temperature drops in the fall, the grubs burrow down below the frost line to avoid being frozen over winter. Naturally, there is nothing for them to eat down that deep in the soil so they survive on all that body fat they put on by eating the roots of your lawn.

Finally in spring, the soil temperature begins to rise and the grubs (who are ravenous after months in hibernation) burrow their way back to the root zone of your lawn. Now the feast begins all over again. After putting on another round of body fat (compliments of your lawn) they pause and pupate; that is, they form a hard shell and begin the transformation into the adult or beetle stage of their life. They will enter this pupae stage during early to mid-June. In mid-July, the beetles emerge from the soil and the cycle begins again.

If you’ve been paying attention, you realize that by the time you get out there in spring with your grub killer, three quarters of the damage the grubs cause has already occurred. This is a classic case of closing the barn doors after the horses have run off.

There’s no way we’ll ever convince the Japanese Beetles to change their habits, so we must try to change ours. The best time to wipe them out is during the hatching period in late August or early September.

All the other beetles that trouble our lawns have similar life cycles resulting in hungry white lawn grubs all hatching and chowing down on the roots of our lawns starting in mid-August.

Remember this: “Apply in July when the beetles fly”
Let’s start with Imidacloprid (Bonide Annual Grub Beater): Ideally, you’ll want to apply Bonide Annual Grub Beater in July and WATER IT IN. By now you must think I’m totally nuts. I just explained how there aren’t any grubs in July because they are all in the beetle form eating the beans and roses. Rest assured, I’m not nuts.

So, I’m supposed to apply grub control in July when there ARE NO GRUBS!!??
The reason Imidacloprid needs to be applied so early is that it needs a month of lead time to get absorbed into the roots of the grass where it remains waiting for the grubs. As soon as the grubs hatch, they begin to eat the roots of the grass. POW! They die.

Good news…Bonide Annual Grub Beater kills ALL white lawn grubs.
That’s the beauty of Imidacloprid. It can’t miss since it’s in the food of the grubs. Properly applied and watered-in, Imidacloprid will kill 98% of the grubs that hatch. No need to lose your lawn…no need to treat again in spring either. Don’t worry, your neighbor’s grubs will stay in his yard. Grubs aren’t much for traveling.

Good news…Milky Spore is a non-chemical grub control

Bad News…Milky Spore ONLY kills Japanese Beetle grubs but not European Chafer and the other white grubs

Milky Spore is a disease that only affects Japanese Beetle grubs. It won’t hurt earthworms or even a bird that eats a grub that has the disease. Milky Spore needs to be applied two or three times a year for three years to reach “epidemic” proportions in the soil. Milky Spore is best applied in spring and late summer/early fall and must get watered in heavily right after application, just like the other grub controls. After that, grubs hatch into your lawn, contract the disease then die, reproducing the disease and spreading it throughout the soil. This happens over and over and soon the entire lawn is protected by the disease spread by their dead bodies. Milky Spore is more expensive up front but will last at least 20 years once it takes hold. Not a bad investment if your main problem is Japanese Beetle grubs.

Water your grubs!!
It is imperative that all grub control products get watered-in thoroughly IMMEDIATELY after application.

Bad news..no rain in the forecast.
Watering in is the biggest problem we face this year with the soil so dry and no soaking rain in the immediate forecast.

DON’T COUNT ON RAIN TO DO THE JOB! Rainfall is never hard enough to get the chemical off the surface of the soil and down to the roots where the grubs are. All grub controls (including Milky Spore) begin to break down as soon as they are out of the bag. Sunlight and air both begin to strip them of their potency the instant they’re out of the bag. Left on the surface of the soil, they will lose about 33% of its potency every 24 hours. As soon as you put your spreader away after you apply the grub control, get the sprinkler out and soak the area with an inch of water. Use an empty tuna fish or cat food can to measure the inch of water. When your sprinkler has filled the can, you’ve applied the correct amount of water. With watering restrictions in place in many communities remember…only apply grub control to as much area as you can effectively saturate with an inch of water. It may take you several days working a section at a time. This will be a tricky year to do it but you’ll want to have your grub control applied and watered in by the end of July for it to work. Thanks for the read.

19 Responses

I would have to disagree about the beetles. Last night while watching a neighbors illegal fireworks from my backyard, the beetles were relentless. We sprayed for the mosquitos, but it didn’t seem to keep away the beetles. I think my large daylily garden is attracting them. After this comment, I’m going to google what to put in a jar to kill them as I knock them off my flowers.

Suzanne,
If the beetles you saw were out at night, they were probably the European Chafers…Japanese Beetle are daytime feeders/fliers. Chafers DO swarm out of the soil at dusk and are nocturnal but won’t be eating your daylilies.

Just put water in the jar with a drop or two of dishwashing or hand soap added.

The soap makes it so the beetles can’t float on top of the water. The beetles (or any insect) will drown in about a minute.

If you get out there early in the morning, the Japanese Beetles will be sluggish in the cooler air. Hold your container (an old saucepan work great) under the foliage where the beetles are and lightly tap the foliage. Japanese Beetles will drop to the ground (this is their escape tactic) but will drop into your soapy water instead. If you get right after the first beetles you see and get rid of them, there will be fewer beetles later on. The female beetles give of a pheromone (scent) that will attract more and more beetles into your yard.

Of course you can spray the plants with Sevin…they eat it, they die. Always read the label and follow the instructions on any pesticide you use.

I’ve had more Japanese beetles this year than ever in Altamont. They have destroyed my climbing roses. They haven’t touched the Blaze rose for some reason. Also all over my new apple trees,,,beans, squash, flowers. I go out a few times every day and knock them into a jar of water and feed them to my chickens. The chickens think they are getting caviar!! I’ve gone through three bottles of seven,,,so frustrating. Thanks for all the advise. I’ll try the grub control this month.

I have the Japanese beetles here too, in Guilderland Center. On flowers I wouldn’t normally think they would be on. I have a small perennial garden of daisy type flowers – daisies, black eyed susans, coneflowers, echineachea, etc. I’m saying to myself, “Really? These flowers too?” Got rid of the climbing roses when I bought the house because they were so bad (literally thousands of them).

Haven’t seen any Japanese Beetles in my yard in Saratoga. LOTS of Chafer beetles though. Interesting to hear they don’t eat foliage-I guess that is some consolation, although eating outside on the patio is interesting. Thanks for the updates Peter.

I have a large bird-feeding station with a couple of feeders that sees tons of activity all day long..the feeders are caged and weight sensitive to keep larger birds from getting to the seed so there is a lot of feeding of the drop offs on the ground by not only birds but squirrels, chipmunks and assorted creatures as well…is it safe to use these insect preventatives near the perimeter of the stations and if not what would be a safe distance?..thanks

I am in Glenmont. Not too many Japanese beetles in my yard. I have seen some Chafer beetles and some Oriental beetles. I never knew the difference they look so similar. More recently I was just able to find out about the Oriental beetles. Never knew what they were. Last year they were terrible. They ate up a lot of my pepper transplants, I had to go out at night constantly and pick them off. This year, they aren’t so bad and they didn’t do any damage to my transplants.

The most problematic for me have been the squash vine borers (which have been horrible the past 2-3 years), cucumber beetles, cabbage worms (which we now have a nice abundance of wasp taking care of those), and some kind of root maggot that for the past two years attacks my bush beans (they eat the roots and the seed) and some of my squash roots early on (don’t seem to bother any of the vining type beans though?).

Since I garden organically, to solve some of these problems, I just try alternate types of plants like now I’ve discovered the borers do not bother the moschata squash so I only plant those. Next year I will plant only vining beans, and I will have to just plant less cuke plants so it is easier to pick the cuke beetles off. The cuke beetles are the worst, I didn’t get any cukes last year. This year I planted less and have been going out religiously with the soap in the cup method. So not too bad because of this.

Thanks for the post. Any ideas on the maggots? I thought they may be corn root maggots because there are a lot of those type of flies and they only seem to bother the bush beans and a few squash. Or, are they some type of beetle larvae? To me from photos, they look like the corn maggot. Any organic tips for that prob?

Yes, you can apply grub control around your daylilies if you wish. However, the beetles lay their eggs mostly in very sunny areas of grass (lawns and meadows) since that is the best food for the baby grubs….daylily roots not so much. Applying grub control under the daylilies will not have any impact on the beetles eating them. The beetles fly and are carried on the wind. The beetles eating your daylilies probably didn’t hatch from the soil below them but from somewhere else.

I’d suggest Diatomaceous Earth for the soil maggots. Dust it on the soil and maybe stir it into the soil an inch or so. DE is the skeletal remains of tiny sea creatures. I looks like dust to us but, on a microscopic level, it is like shards of glass. DE is so sharp that it slices into the bodies of insects and they die from fluid loss and dehydration. Diatomaceous Earth is handy stuff for the gardener to have around since it is effective against so many insects. You can buy DE at any well stocked garden center including Hewitt’s.

Was just checking on the web to see what others were experiencing with Japanese beetles this year. They usually show up at the end of June, but this year I haven’t seen even one (I live in Delhi, NY). I have a horticulture degree and entomology experience so I am very familiar with their life cycle. That makes sense that the grubs were killed by the saturated soil after the flooding last Aug. This area was hit extremely hard because of the rain rushing down the mountains. I certainly won’t miss all of the damage they cause! Great info on your site. I will check back often!

Two Japanese Beetles in my Latham yard last weekend and none spotted since then. Usually they’re nailing my Knockout Roses but so far nada. On the other hand I am seeing an increase in the vole population (“Havoc” nails them in one feeding; chipmunks require a bit more). Also a bumper crop of yellow jackets, mostly hanging around the bird baths looking for water.

I plan to build a simple OJ and dish soap trap as a first step. If I manage to locate the nest it’s a goner, thanks to wasp and hornet spray.

Another major pest this year is earwigs!!! I’ve been spraying the foundation and mulch but they keep on coming. I just found two of the $&@? things on my hummingbird feeder!! My guess is this drought is forcing them to search for water.

Earwigs are so gross. They’re one of the critters I really can’t tolerate and I’ve been finding a lot this year! Not sure what’s worse – earwigs or house centipedes. So far so good with the centipedes though.

Anyway, I’m so glad we talked a couple weeks ago and you told me about the European chafer beetles so I can treat for them properly. They get everywhere – in the lights, in the dog’s water dish, in my hair. And the countless grubs – I can’t believe how many! Yuck!

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